# Tips for writing answers in Homi Bhabha Online Practical Exam

This year Homi Bhabha Practical Exam (Level 2) is Online! For each experiment, you have to write the answers on an answer sheet and upload the photograph. So although the name is “practical exam”, your score mainly depends upon how nicely you write the answers!

## 1. Final answer should be neat and clear.

No cancellation and over-writing in final answer. Digits and decimal points should be very clear.

If you have to change the answer — cancel it completely, leave some space and rewrite the correct answer.

## 2. UNITS are a MUST

(See, the same answers have got zero marks in the first case!!)

## 3. Show formulas and calculations.

If you have used some formula or principle, DO mention it. If you have done some calculations, show them.

Write a couple of steps that will show how you arrived at the final answer. This will tell the examiner that you have indeed found the answer yourself and not copied it from someone else.

## 4. Measure Accurately, not approximately

While taking the reading, do NOT round off the answer. All measurements should be as accurate as the given instrument allows.

E.g. If the length of the object you have measured / observed is 6.2 cm, you should not round it off to 6 cm. Later if the calculation becomes difficult, at that point you can round off the values and write approximate answer at the end.

E.g. You may write:
Length = 6.2 cm
Height = 1.1 cm
Volume = L x B x H
= 6.2 cm x 2.1 cm x 1.1 cm
= (approximately) 6 x 2 x 1
= 12 cu cm

## 5. Check the least count of the instrument

While observing readings in measuring cylinder, beaker, spring balance, etc. students often forget to check the least count.

E.g. What reading does this spring balance show?

Students often write the above reading as “410 gm”. But if you observe carefully, the least count is 20 gm – So the reading is actually 420 gm.

## 6. Write ALL the answers

In Homi Bhabha practical exam some questions are based on the activities of the experiment performed while some questions are based on the theory which you have studied earlier. Even though such theory questions do not depend upon the experiment, they do carry marks.
So do ensure that you answer all the questions.

## 7. Write scientific answers, not essays!

For descriptive questions like – ‘Explain your method / reason’ or ‘why does this happen?’ – you are expected to write short and scientific answers.

Underline the scientific principle used, if any. Do NOT write long essays like this –

Your answer should be short and logical. English language skills are not important. You can make shortcuts to save time. A good quality answer should have scientific terms which show your understanding.

Do mention the scientific principles involved in the experiment (even if not asked) – e.g. repulsion of magnets, neutralization of acid-base, refraction of light, etc.

E.g. In one experiment, water, thermometer, glucose powder was given. You were asked to measure the temperature of water (it was 29 deg C). Then add glucose powder and measure the temperature again (it became 27 deg C)
The question was: What change in temperature do you observe?

Now, if you write “temperature becomes 27 degrees C” it is incorrect! Because you are asked the “change” in temperature and NOT “what is the new temperature”.

So the correct answer is “The temperature drops by 2 degrees Centigrade (from 29 degrees to 27 degrees)

## 9. Use Common-sense

E.g. – The sample shown below was kept and the question was – “Which part of this plant is reduced?”

A student said that he could not identify the plant and so he did not answer the question.
But actually the name of the plant was not asked at all. Now the leaves and roots are very clearly visible. So they are definitely not reduced. So ‘stem’ is the only one that must be reduced.